Preparation And Oil/Water Separation Performance Of Three-dimensional Porous Hydrophobic/Lipophilic Materials

With the frequent occurrence of oil spill accidents and the increase of oily wastewater from the petroleum industry,the damage of oil-water mixture to the ecosystem is becoming more and more serious.Using oil/water separation materials to treat oily wastewater is an effective method which can also recover resources.The performance of the oil/water separation materials is affected by factors such as pore size,pore length and oil viscosity.The theoretical research on those factors is of great significance.In this paper,acrylate-based porous hydrophobic/lipophilic materials were prepared by 3D printing technology and surface modification.The surface morphology and wettability of the prepared materials were characterized.The effects of pressure,pore size and oil viscosity on the flow rate were studied.The experimental results show that the prepared material is hydrophobic/lipophilic with the maximum contact angle of 136.9 °.The oil/water separation efficiencies of gasoline,diesel oil,diesel oil,motor oil 10# and motor oil 20# are higher than 98%.The flow rate is inversely proportional to the viscosity in the range from 0.003 to 0.005 Pa·s.The flow rate rises exponentially with the increase of pore size in the range from 0.8 to 2 mm with 1.4 mm as a turning point.Three-dimensional hydrophobic/lipophilic materials were prepared by dip-coating method with stainless steel meshes as the raw materials.The surface morphology and wettability of the prepared materials were characterized.Three important factors of the mesh,namely the mesh number,the number of layers,the oil viscosity,and their interactions were studied.The experimental results show that the 100 mesh screen exhibits the best hydrophobicity and the largest contact angle of 136.3°.For the 4-layer stainless steel mesh,the oil/water separation efficiencies of gasoline and motor oil 10# are 98.18% and 99.13%,respectively.The influences of oil viscosity,the mesh number,and the number of layers on the oil/water separation efficiency decrease orderly under the current experimental conditions.The interaction between mesh number and oil viscosity is the most significant.In practical applications,the most important thing is to choose the appropriate mesh number of stainless steel mesh according to oil viscosity.The PS/PU composite membrane was produced by electrospinning technique.The microstructure and wettability of the membrane were characterized by SEM,optical microscopy,and contact angle measurement.Oil/water separation performance,corrosion resistance,and emulsified oil separation performance of the membrane were tested.The experimental results show that the optimum spinning conditions are as follows: the solvent DMF/THF volume ratio is 2: 3,the concentration of polymer solution is 20(m/v)%,the mass ratio of PS/PU is 1:1,the voltage is 15 KV,and the spinning height is 15~16 cm.Under these conditions,the largest water contact angle of the prepared PS/PU composite membrane is 137 °,and the oil contact angle is almost 0°.The prepared membrane shows excellent hydrophobic/lipophilic properties.The separation efficiency of the membrane for gasoline and water is 99%.The oil content in the emulsified oil can be reduced from 2000 ppm to 11 ppm after one treatment with the prepared membrane.